diff --git a/apps/stage-pocket/src/components/DataGui/DualEndRange.vue b/apps/stage-pocket/src/components/DataGui/DualEndRange.vue
index 741c0bc5e..8d132299d 100644
--- a/apps/stage-pocket/src/components/DataGui/DualEndRange.vue
+++ b/apps/stage-pocket/src/components/DataGui/DualEndRange.vue
@@ -73,7 +73,7 @@ const sortedValues = computed(() => {
 
 const sliderStyle = computed(() => {
   const sliderOffset = valueToPercent(sortedValues.value[0], props.min, props.max)
-  const sliderLeap = valueToPercent(sortedValues.value.at(-1), props.min, props.max) - sliderOffset
+  const sliderLeap = valueToPercent(sortedValues.value.at(-1)!, props.min, props.max) - sliderOffset
   return {
     left: `${sliderOffset}%`,
     width: `${sliderLeap}%`,
diff --git a/apps/stage-tamagotchi/src/renderer/widgets/map/components/Map.vue b/apps/stage-tamagotchi/src/renderer/widgets/map/components/Map.vue
index 473285f80..5698c621f 100644
--- a/apps/stage-tamagotchi/src/renderer/widgets/map/components/Map.vue
+++ b/apps/stage-tamagotchi/src/renderer/widgets/map/components/Map.vue
@@ -74,7 +74,7 @@ const routePoints = computed(() => {
     return [resolvedOrigin.value, resolvedDestination.value]
 
   const first = points[0]
-  const last = points.at(-1)
+  const last = points.at(-1)!
   if (first.x !== resolvedOrigin.value.x || first.y !== resolvedOrigin.value.y)
     points.unshift(resolvedOrigin.value)
   if (last.x !== resolvedDestination.value.x || last.y !== resolvedDestination.value.y)
diff --git a/apps/stage-web/src/components/DataGui/DualEndRange.vue b/apps/stage-web/src/components/DataGui/DualEndRange.vue
index 741c0bc5e..8d132299d 100644
--- a/apps/stage-web/src/components/DataGui/DualEndRange.vue
+++ b/apps/stage-web/src/components/DataGui/DualEndRange.vue
@@ -73,7 +73,7 @@ const sortedValues = computed(() => {
 
 const sliderStyle = computed(() => {
   const sliderOffset = valueToPercent(sortedValues.value[0], props.min, props.max)
-  const sliderLeap = valueToPercent(sortedValues.value.at(-1), props.min, props.max) - sliderOffset
+  const sliderLeap = valueToPercent(sortedValues.value.at(-1)!, props.min, props.max) - sliderOffset
   return {
     left: `${sliderOffset}%`,
     width: `${sliderLeap}%`,
diff --git a/packages/stage-ui/src/components/gadgets/time-series-chart.vue b/packages/stage-ui/src/components/gadgets/time-series-chart.vue
index 7e58c8b74..9eb586b7c 100644
--- a/packages/stage-ui/src/components/gadgets/time-series-chart.vue
+++ b/packages/stage-ui/src/components/gadgets/time-series-chart.vue
@@ -166,7 +166,7 @@ function downsampleSeries(values: readonly number[], maxPoints: number) {
   }
 
   // Ensure the last value remains the most recent value (avoid averaging it away)
-  result[result.length - 1] = values.at(-1)
+  result[result.length - 1] = values.at(-1)!
   return result
 }